The present invention relates to a method of and an apparatus for setting a projectile time fuse.
The method according to the invention is particularly applicable to high-acceleration resistant, high-accuracy, time fuzes, especially electronic-type time fuzes, or enables the use of these fuzes and improves their accuracy.
The projectile fuze's event times are set at appropriate devices prior to firing, e.g., by programming, on the basis of a number of factors such as the distance to the target.
The time fuzes of the hitherto used mechanical-clockwork type have a relatively low setting accuracy on the order of 50 msec. Thus, event time dispersion is very large, particularly as far as high-velocity projectiles are concerned. Because of this, electronic time fuzes which generally achieve a much higher accuracy are preferred.
The most accurate time fuzes at present are based on the use of crystal clocks that serve as time measuring instruments. Because of their special construction, crystal units withstand acceleration loads to a limit extent only. They are destroyed by acceleration loads of 5,000 to 10,000 g, and change their frequency even at lower accelerations. This results in crystal clocks being used in rocket fuzes only, since the maximum rocket acceleration is only a few thousand g. Projectiles fired from guns are subjected to accelerations of 50,000 g and above. Thus, the installation of crystal clocks into projectiles is not possible. This is one of the reasons why the accuracy of standard projectile time fuzes is quite insufficient; the event time dispersion as related to the firing range is generally larger than 1 percent.